The Door County peninsula has been inhabited for about 11,000 years. Artifacts from an ancient village site at Nicolet Bay Beachhave been dated to about 400 BC. This site was occupied by various cultures until about 1300 AD.
The 18th and 19th centuries saw the immigration and settlement of pioneers, mariners, fishermen and farmers, with the first white settler being Increase Claflin. Economic sustenance came from lumbering and tourism.
During the 18th century, Door County was actually referred to as "Death's Door territory" by the French, the water strait between what is now the Door Peninsula and Washington Island is very hazardous for navigating ships. This led to (and continues to cause) many vessels being damaged and shipwrecks, hence the name.
During the 19th century, various groups of Native Americans occupied the area that would become Door County and its islands. Beginning in mid-century, these Indians, mostly Potawatomi, were removed from the peninsula by the federal government under the Indian Removal Act of 1830. Later in the 19th century there was a fairly large-scale immigration of BelgianWalloons, who populated a small region in the county.